This invention relates to bituminous compositions and, more particularly, asphaltic compositions which are suitable for use as roofing materials.
Asphalt is a natural constituent of crude oils and is typically produced from the distillation residues of refining feedstocks. This product is of very significant industrial importance since it is widely used in the construction of roads, building materials and other industrial applications. This asphalt has normally been obtained from conventionl petroleum oils.
With the changing economics of the petroleum industry, there is a trend toward the conversion of heavy hydrocarbon oils, such as the distillation residues, to light and intermediate naphthas of good quality for reforming feedstock, fuel oil and gas oils. These residues represent the normal sources of asphalts.
Roofing asphalts are also obtained from distillation residues, but normally require considerable air blowing to attain the desired properties for binding, adhesion, water proofing etc. Diverse applications of air blown bitumen have resulted in the development of standard specifications for various uses.
Asphalt specifications for roofing purposes are given in Table I below:
TABLE I ______________________________________ Asphalt requirements for roofing purposes Type 1 Type 2 Type 3 Property Min. Max. Min. Max. Min. Max. ______________________________________ Softening Point 60 68 75 83 90 98 (R & B, .degree.C.) Flash Point 230 -- 230 -- 230 -- (C.O.C. .degree.C.) Penetration 0.degree. C., 200 g, 60 s 10 -- 10 -- 8 -- 25.degree. C., 100 g, 5 s 30 45 20 30 15 25 45.degree. C., 50 g, 5 s -- 160 -- 80 -- 55 Thin film oven test 80 -- 80 -- 80 -- pen., % of original Loss of volatiles, % -- 1.0 -- 1.0 -- 1.0 Solubility in 99 -- 99 -- 99 -- trichloroethylene, % ______________________________________
It is the object of the present invention to develop a blended roofing asphalt which can utilize unwanted processing residues, while avoiding the need of the costly air blowing process.